This riveting documentary about nuclear weapons becomes deeply worrying as it outlines a seriously unstable global situation, carefully exposing how easy it would be for a terrorist to set off a nuclear bomb.

The hypothesis comes from John F Kennedy: "Every man, woman and child lives under a nuclear sword of Damocles, hanging by the slenderest of threads, capable of being cut at any moment by accident or miscalculation or by madness." And gifted filmmaker Walker kicks off with images of horrific terrorist attacks all over the world, noting that if terrorists get hold of nuclear weapons they won't hesitate to use them. Especially since al-Qaeda's stated goal is to kill 4 million people, as many as they say the West has killed in the Arab world.

If you weren't glued to the news channels in late 2006 you might have missed the controversy: Other words started being used to describe this gentle man, words that until that point would have been thought unlikely. Words like: Anti-Semite. Racist. Plagiarist. Hatemonger. Terrorist sympathizer.

OK, here's the setup. Eric Saperston graduates from college, and rather than getting a job, he decides to do the most cliched thing you can do: To buy a VW bus and follow the Grateful Dead around the country.

Erk, scratch that. That's a movie that's been made before -- a lot, and never very well.